Katherine Y. Barnes, an Arizona law professor with a Ph.D. in statistics, mounts what appears to be a strong challenge to Richard Sander's conclusion that affirmative action causes minority students to fail the bar exam when they otherwise would have passed. However, as I skimmed Barnes's article, I saw no discussion of whether affirmative action itself may create some of the hostile learning environment and stereotype threat that under-represented minority students face. That is, if students and professors believe that African American and Latino students are less capable than white and Asian students, because the former were admitted under an affirmative action program and the latter on a "merit-based" system, this itself may be a significant source of discriminatory attitudes that impede minority students' learning. Even more disturbingly, if affirmative action programs cause minority students to believe themselves less capable than their classmates, the stereotype can become a self-fulfilling prophecy.
I don't know what would be a workable solution to this problem, and indeed I suspect that even if a school abruptly ended racial preferences in admissions, there would be a significant overhang of negative attitudes toward the abilities of minority students. In my experience, white conservatives especially often assume that someone who could be an affirmative action beneficiary must be one, and that if the number of African Americans at an institution isn't significantly reduced after the declared end of racial affirmative action (and sometimes even if it has declined tremendously, as in UCLA's 2006 freshman class), that the program must be continuing in some obscure, secret fashion.